Various types of saw blades are known in the art for cutting workpieces having different shapes and formed of different types of materials. For example, band saw blades often may be used for cutting larger workpieces formed of various types of metal or metal alloys. A band saw blade generally may be formed as a continuous band including a cutting edge and a back edge located on an opposite side of the saw blade relative to the cutting edge. The cutting edge may include a number of teeth configured to engage and cut a workpiece, and the back edge may include a linear or contoured surface configured to engage spaced rollers of a band saw machine. During operation of the band saw machine, the band saw blade may move in a cutting direction and a feed direction, and the rollers may apply pressure to the back edge as the opposing cutting edge cuts through the workpiece. Some band saw blades may have a bi-metal configuration, with a backing formed of a first metal and a number of tips formed of a second metal and welded to the backing. In this manner, each tooth may include a base portion formed of the first metal, a tip portion formed of the second metal, and a weld zone extending along the interface of the base portion and the tip portion. In some instances, the first metal may be a spring steel, and the second metal may be a tool steel.
Certain band saw blades may be designed for cutting large structural workpieces, such as I-beams, tubes, channels, pipes, or other structural members intended for industrial building purposes. Structural workpieces may be formed of steel or similar materials, may have relatively large wall thicknesses (e.g., equal to or greater than ¾ inches), and may include one or more weld zones. Cutting large structural workpieces, as opposed to solid workpieces, may present certain challenges in view of the high-impact nature of the cutting application. For example, as a band saw blade cuts through a large structural workpiece, multiple separate regions of tooth engagement may exist, with an impact loading associated with each region. The multiple regions of tooth engagement may result in increased occurrence of tooth damage, such as chipped teeth (i.e., removal of a portion of a tooth) or stripped teeth (i.e., failure of a tooth along the weld zone). Moreover, respective lengths of tooth engagement of the separate regions may change significantly as the band saw blade advances through the structural workpiece in the feed direction. As a result, the number of teeth engaging the workpiece may be greater than or less than the ideal range for efficient cutting at different points along the cut. Certain large structural workpieces may include highly localized “hard” regions which may increase a load experienced by the saw blade. For example, large structural tubes may include a linear weld. Such highly localized hard regions may result in increased occurrence of tooth damage as the band saw blade passes therethrough. In some instances, the fabrication of certain large structural workpieces may result in significant residual stresses in the material (i.e., the material may be in tension or compression), which may be relaxed during cutting of the workpiece. Such relaxation may result in the material expanding into the cut, thereby trapping the saw blade in a phenomenon known as “blade pinching.” Although this may be an issue with cutting various types of large structural workpieces, blade pinching often may be a major concern when cutting a relatively long web section (e.g., having a length equal to or greater than 30 inches) of an I-beam. Ultimately, these challenges in cutting large structural workpieces may reduce the useful life of the band saw blade and necessitate frequent replacement.